Nickel‐Catalyzed Conversion of Enol Triflates into Alkenyl Halides
作者:Julie L. Hofstra、Kelsey E. Poremba、Alex M. Shimozono、Sarah E. Reisman
DOI:10.1002/anie.201906815
日期:2019.10.14
A Ni-catalyzed halogenation of enol triflates was developed and it enables the synthesis of a broad range of alkenyl iodides, bromides, and chlorides under mild reaction conditions. The reaction utilizes inexpensive, bench-stable Ni(OAc)2 ⋅4 H2 O as a precatalyst and proceeds at room temperature in the presence of sub-stoichiometric Zn and either 1,5-cyclooctadiene or 4-(N,N-dimethylamino)pyridine
开发了镍催化的烯醇三氟甲磺酸酯卤化反应,能够在温和的反应条件下合成多种烯基碘化物、溴化物和氯化物。该反应使用廉价、实验室稳定的 Ni(OAc)2·4 H2 O 作为预催化剂,并在亚化学计量的 Zn 和 1,5-环辛二烯或 4-(N,N-二甲基氨基) 存在下在室温下进行吡啶。
Intermolecular Reductive Heck Reaction of Unactivated Aliphatic Alkenes with Organohalides
A general intermolecular reductive Heckreaction of organohalides with both terminal and internal unactivated aliphatic alkenes has been first realized in high yield with complete anti-Markovnikov selectivity. The challenging vinyl bromides, aryl chlorides, and polysubstituted internal alkenes were first applied. More than 100 remote carbofunctionalized alkyl carboxylic acid derivatives were rapidly
substituted benzylic manganese chlorides were prepared by insertion of magnesium turnings in the presence of MnCl2·2LiCl in THF at −5 °C within 2 h. These benzylic manganese reagents underwent smooth cross-couplings with various functionalized alkenyl iodides, bromides, and triflates or iodoacrylates in the presence of 10 mol % FeCl2 at 25 °C for 1–12 h. Mechanistic studies showed that benzylic manganese